Stone-grinding machine



Allg. 27, 1929. E, A CHASE 1,725,899

STONE GRINDING MACHINE Filed May 20, 1926 Patented Aug. 27, 1929.

massa UNITED STATES PATENT OFFICE.

ELROY A. CHASE, OF NORTI-IFIELD, VEIQMGNT.r

STONE-GRINDING MACHINE.

Application filed May 20,

This invention relates to machines particularly adapted for grinding or polishing stone, such as memorial tomb stones or monuments of granite, marble or similar material. 4

lt is common in the art of stone cutting and grinding to utilize rotating grinding wheels for grinding the stone. Vhen such wheels are used it is desirable that the pressure of the wheel or tool on the work be varied for different conditions of use. For instance, in roughing or initial grinding, a heavy pressure is desirable, whereas in finishing the surface a light pressure may be used. Furthermore, it is desirable that the machine be so constructed that the tool can be easily and readily maneuvered or moved relatively to the work with the expenditure of a minimum amount of effort on the part of the operator.

rlhis invention has for its object, therefore, to provide a grinding machine so constructed and arranged that the pressure of the tool on the work can be varied to suit requirements, and furthermore, it is so constructed that the tool can be maneuvered on the work with the expenditure of a minimum amount of effort on the part of the operator. Y

Another object of the invention is to provide a machine of the character described so constructed and arranged thatl varying'pressure of the tool on the work will have no appreciable effect on the ease of movement of the tool with reference to the worlr.

Further objects of the invention will ap-A pear from the following description, taken` in combination with the drawings, which form part of this application, and in which Fig. 1 is an elevational view showing the machine constructed in accordance with this invention; l

Fig. 2 is a transverse sectional elevation talren through the frame andthe supporting means therefor;

Fig. 3 is a diagrammatic top plan view, showing the arrangement of certain parts; and 1 Fig. il is a perspective view of a block of stone on which the grinding tool' may be used.

The invention briefly described consists of a grindingmachine comprising a frame having a tool rotatably mounted at one end thereof, the other end of the frame being 192e. Serial No. 110,566.

mounted 0n a support in such a manner that the fra-me and tool carried thereby can be tilted vertically, angledabout a vertical axis,

'or moved longitudinally with reference to the work and to the support.

rlhe frame carries means a-djustably mounted thereon for varying the pressure of the tool on the work and disposed inter'- mediate the work and the frame support. The frame is mounted lon a tiltable and angularly adjustable cradle which in turn is mounted on a carriage adapted for movement longitudinally of the support. The fra-me is so mounted that irrespective of the amount of pressure exerted on the work by the tool, the frame can be easily swung or tilted and the tool may be easily and readily maneuvered without requiring the expenditure of any substantial force or effort on the part of the operator.

Further details will appear from the following description. i

In the particular form of the invention illustrated, the machine comprises an elongated frame 10 having a grinding shaft 11 rotatably mounted adjacent to one end thereof, the shaft being connected through a universal joint to a grinding wheel or 500112, which operates on the upper surface of the block 13 of stone.

The grinding shaft 1l has secured thereto a pulley 15 which is driven by a belt 16 from a pulley 17 secured to a shaft 18 of a motor 19, the motor being supported on the opposite end of the frame 10 from that which carries the shaft 11. YThe belt 16 isk maintained at the desired tension/by means of an idler 20.

The frame 10 is supported adjacent to one end in a cradle 25 carrying wheels 26 engaging the yupper surface of a flat plate 27, which is mounted on a carriage 28. The carriage 28 has two pairs of wheels 29-30 mounted on rails 31 and 32 secured to a support 33, the rails being preferably disposed substantially horizontally.

The cradle 25 has secured thereto, and eX- tending downwardly therefrom, a king bolt 35 which passes through an opening 86 in the plate 27 and through a conical opening 37 in the body of the carriage 28. A nut 38 and washer 39 are secured tothe lower end of the king bolt.

In order to provide for varying the pressure of the tool on the work, a weight 45 is adjustably mounted on the frame 10. The weight is preferably mounted on wheels 46 and 47, which in turn aremounted on rails i8 formed at the upper surface of the frame l0. In order to adjust the weight a cable 50 is secured at its ends 5l and 52 to the weight and extends around pulleys or idlers 53 and 54:, which are mounted on opposite sides of the wheels 26 and king bolt 35, and around a drum 55 carried by a shaft 56. A crank 57 is secured to the shafty 56, and by tur ing vthis crank the cable can be shifted, thus adjusting the weight to various positions between limits on opposite sides of the support or pivot for the frame.

A handle 60 is secured to the front of the frame, and the wheel can be readily moved about over the stone by means of this handle.

From the foregoing description it will be seen that the tool l2 can be swung longitudinally or laterally of the work 13, and can be raised or lowered to accommodate the contour of the upper surface of the block being ground. In other words, the tool can be easily and readily maneuvered to any desired position and since the carriage 28 and the cradle 25 are supported in horizontal planes, the position of adjustment of the weight 45 or the pressure of the tool on the work will have no appreciable effect on the maneuvering of the tool.

For instance, movement of the tool across or transversely of the st-one will cause the rollers or wheels of the carriage to roll on the tracks 31, 82 without in anyway changing the balance of the frame. Furthermore, angling the frame up and down when work` ing on a curved surface such as the top of the block in Fig. i does not interfere with the control of the tool due to the support of the frame in the horizontal planes formed by plate 27 and track rails 3l, 32.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed otherwise than as set forth in the claims, but what I claim is l. A grinding machine comprising a support, a frame mounted intermediate its ends on said support soas to permit pivotal movement of the frame in a vertical plane, said frame also being mounted for pivotal movement in a horizontal plane and for movement longitudinally of the support, an abrading tool rotatably mounted on the frame adjacent to one end, means adjacent to the other end of the frame -for rotating said tool, and a weight movable along said frame between limits on opposite sides of the pivotal support to vary the pressure of the abrading tool on the work.

2. A grinding machine comprising a s up-z port, a frame mounted, intermediate its ends messes on said support so as to permit pivotal movementY of the frame in vertical and horizontal planes and for movement longitudinally of the support, an abrading tool rotatably mounted on the frame adjacent to one end, means adjacent to the other end of the frame for rotating said tool, and a universal joint associated with the drive to said tool to permit it to follow the contour of the work irrespective of the relative position of said frame, whereby work pieces of various sizes and shapes may be accommodated, a weight movable along said frame to vary the pressure of the abrading tool on the work, and

means operable from a point adjacent to the work for moving said weight along the frame, said tool rotating means being disposed onthe opposite side of the pivotal frame support from the tool whereby to serve as a counterbalance for the frame.

3. A grinding machine comprising a support, a frame mounted intermediate its ends on said support so as to permit pivotal movement of the frame in vertical and horizontal planes and for movement longitudinally of the support, an abrading tool rotatably mounted on said frame adjacent to one end, means adjacent to the other end of the frame for rotating said tool, and a uni` versal joint associated with the drive to said tool to permit it to follow the contour of the work irrespective of the relative position of said frame, whereby work pieces of various size and shapes may be accommodated,

a weight movable along said frame between limits on opposite sides of the pivotal support tovary the pressure of the abrading tool on the work, and means operable from a point adjacent to the work for moving said weight along the frame.

,4. A grinding machine comprising a support, an elongate frame universally mounted intermediate its ends on said support, a

shaft journalled adjacent to one end of saidY frame, an abrading tool connected to said shaft by a universal joint and adapted to be rotated by said shaft, whereby said tool is `adapted to follow the contour of the work in any position of said frame, a motor on the end of the frame remote from said shaft and serving as a counterbalance, means for operatively connecting said motor and said shaft, a weight car adapted to run along said frame between limits on opposite sides of its point of support, a cable fastened at either end to said car, and means adjacent to the end of the frame in which said shaft is journalled for operating said cable to move the weight car and thereby control the pressure of the tool on the work.

In testimony whereof I have hereunto af- Xed'my signature. i

Ensor A, cnasn. 

